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<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> xiaoming = {
    name: <span class="hljs-string">&apos;&#x5C0F;&#x660E;&apos;</span>,
    birth: <span class="hljs-number">1990</span>
};
</code></pre>
<p>&#x4F46;&#x662F;&#xFF0C;&#x5982;&#x679C;&#x6211;&#x4EEC;&#x7ED9;<code>xiaoming</code>&#x7ED1;&#x5B9A;&#x4E00;&#x4E2A;&#x51FD;&#x6570;&#xFF0C;&#x5C31;&#x53EF;&#x4EE5;&#x505A;&#x66F4;&#x591A;&#x7684;&#x4E8B;&#x60C5;&#x3002;&#x6BD4;&#x5982;&#xFF0C;&#x5199;&#x4E2A;<code>age()</code>&#x65B9;&#x6CD5;&#xFF0C;&#x8FD4;&#x56DE;<code>xiaoming</code>&#x7684;&#x5E74;&#x9F84;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> xiaoming = {
    name: <span class="hljs-string">&apos;&#x5C0F;&#x660E;&apos;</span>,
    birth: <span class="hljs-number">1990</span>,
    age: <span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params"></span>) </span>{
        <span class="hljs-keyword">var</span> y = <span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>().getFullYear();
        <span class="hljs-keyword">return</span> y - <span class="hljs-keyword">this</span>.birth;
    }
};

xiaoming.age; <span class="hljs-comment">// function xiaoming.age()</span>
xiaoming.age(); <span class="hljs-comment">// &#x4ECA;&#x5E74;&#x8C03;&#x7528;&#x662F;25,&#x660E;&#x5E74;&#x8C03;&#x7528;&#x5C31;&#x53D8;&#x6210;26&#x4E86;</span>
</code></pre>
<p>&#x7ED1;&#x5B9A;&#x5230;&#x5BF9;&#x8C61;&#x4E0A;&#x7684;&#x51FD;&#x6570;&#x79F0;&#x4E3A;&#x65B9;&#x6CD5;&#xFF0C;&#x548C;&#x666E;&#x901A;&#x51FD;&#x6570;&#x4E5F;&#x6CA1;&#x5565;&#x533A;&#x522B;&#xFF0C;&#x4F46;&#x662F;&#x5B83;&#x5728;&#x5185;&#x90E8;&#x4F7F;&#x7528;&#x4E86;&#x4E00;&#x4E2A;<code>this</code>&#x5173;&#x952E;&#x5B57;&#xFF0C;&#x8FD9;&#x4E2A;&#x4E1C;&#x4E1C;&#x662F;&#x4EC0;&#x4E48;&#xFF1F;</p>
<p>&#x5728;&#x4E00;&#x4E2A;&#x65B9;&#x6CD5;&#x5185;&#x90E8;&#xFF0C;<code>this</code>&#x662F;&#x4E00;&#x4E2A;&#x7279;&#x6B8A;&#x53D8;&#x91CF;&#xFF0C;&#x5B83;&#x59CB;&#x7EC8;&#x6307;&#x5411;&#x5F53;&#x524D;&#x5BF9;&#x8C61;&#xFF0C;&#x4E5F;&#x5C31;&#x662F;<code>xiaoming</code>&#x8FD9;&#x4E2A;&#x53D8;&#x91CF;&#x3002;&#x6240;&#x4EE5;&#xFF0C;<code>this.birth</code>&#x53EF;&#x4EE5;&#x62FF;&#x5230;<code>xiaoming</code>&#x7684;<code>birth</code>&#x5C5E;&#x6027;&#x3002;</p>
<p>&#x8BA9;&#x6211;&#x4EEC;&#x62C6;&#x5F00;&#x5199;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">getAge</span>(<span class="hljs-params"></span>) </span>{
    <span class="hljs-keyword">var</span> y = <span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>().getFullYear();
    <span class="hljs-keyword">return</span> y - <span class="hljs-keyword">this</span>.birth;
}

<span class="hljs-keyword">var</span> xiaoming = {
    name: <span class="hljs-string">&apos;&#x5C0F;&#x660E;&apos;</span>,
    birth: <span class="hljs-number">1990</span>,
    age: getAge
};

xiaoming.age(); <span class="hljs-comment">// 25, &#x6B63;&#x5E38;&#x7ED3;&#x679C;</span>
getAge(); <span class="hljs-comment">// NaN</span>
</code></pre>
<p>&#x5355;&#x72EC;&#x8C03;&#x7528;&#x51FD;&#x6570;<code>getAge()</code>&#x600E;&#x4E48;&#x8FD4;&#x56DE;&#x4E86;<code>NaN</code>&#xFF1F;<em>&#x8BF7;&#x6CE8;&#x610F;</em>&#xFF0C;&#x6211;&#x4EEC;&#x5DF2;&#x7ECF;&#x8FDB;&#x5165;&#x5230;&#x4E86;JavaScript&#x7684;&#x4E00;&#x4E2A;&#x5927;&#x5751;&#x91CC;&#x3002;</p>
<p>JavaScript&#x7684;&#x51FD;&#x6570;&#x5185;&#x90E8;&#x5982;&#x679C;&#x8C03;&#x7528;&#x4E86;<code>this</code>&#xFF0C;&#x90A3;&#x4E48;&#x8FD9;&#x4E2A;<code>this</code>&#x5230;&#x5E95;&#x6307;&#x5411;&#x8C01;&#xFF1F;</p>
<p>&#x7B54;&#x6848;&#x662F;&#xFF0C;&#x89C6;&#x60C5;&#x51B5;&#x800C;&#x5B9A;&#xFF01;</p>
<p>&#x5982;&#x679C;&#x4EE5;&#x5BF9;&#x8C61;&#x7684;&#x65B9;&#x6CD5;&#x5F62;&#x5F0F;&#x8C03;&#x7528;&#xFF0C;&#x6BD4;&#x5982;<code>xiaoming.age()</code>&#xFF0C;&#x8BE5;&#x51FD;&#x6570;&#x7684;<code>this</code>&#x6307;&#x5411;&#x88AB;&#x8C03;&#x7528;&#x7684;&#x5BF9;&#x8C61;&#xFF0C;&#x4E5F;&#x5C31;&#x662F;<code>xiaoming</code>&#xFF0C;&#x8FD9;&#x662F;&#x7B26;&#x5408;&#x6211;&#x4EEC;&#x9884;&#x671F;&#x7684;&#x3002;</p>
<p>&#x5982;&#x679C;&#x5355;&#x72EC;&#x8C03;&#x7528;&#x51FD;&#x6570;&#xFF0C;&#x6BD4;&#x5982;<code>getAge()</code>&#xFF0C;&#x6B64;&#x65F6;&#xFF0C;&#x8BE5;&#x51FD;&#x6570;&#x7684;<code>this</code>&#x6307;&#x5411;&#x5168;&#x5C40;&#x5BF9;&#x8C61;&#xFF0C;&#x4E5F;&#x5C31;&#x662F;<code>window</code>&#x3002;</p>
<p>&#x5751;&#x7239;&#x554A;&#xFF01;</p>
<p>&#x66F4;&#x5751;&#x7239;&#x7684;&#x662F;&#xFF0C;&#x5982;&#x679C;&#x8FD9;&#x4E48;&#x5199;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> fn = xiaoming.age; <span class="hljs-comment">// &#x5148;&#x62FF;&#x5230;xiaoming&#x7684;age&#x51FD;&#x6570;</span>
fn(); <span class="hljs-comment">// NaN</span>
</code></pre>
<p>&#x4E5F;&#x662F;&#x4E0D;&#x884C;&#x7684;&#xFF01;&#x8981;&#x4FDD;&#x8BC1;<code>this</code>&#x6307;&#x5411;&#x6B63;&#x786E;&#xFF0C;&#x5FC5;&#x987B;&#x7528;<code>obj.xxx()</code>&#x7684;&#x5F62;&#x5F0F;&#x8C03;&#x7528;&#xFF01;</p>
<p>&#x7531;&#x4E8E;&#x8FD9;&#x662F;&#x4E00;&#x4E2A;&#x5DE8;&#x5927;&#x7684;&#x8BBE;&#x8BA1;&#x9519;&#x8BEF;&#xFF0C;&#x8981;&#x60F3;&#x7EA0;&#x6B63;&#x53EF;&#x6CA1;&#x90A3;&#x4E48;&#x7B80;&#x5355;&#x3002;ECMA&#x51B3;&#x5B9A;&#xFF0C;&#x5728;strict&#x6A21;&#x5F0F;&#x4E0B;&#x8BA9;&#x51FD;&#x6570;&#x7684;<code>this</code>&#x6307;&#x5411;<code>undefined</code>&#xFF0C;&#x56E0;&#x6B64;&#xFF0C;&#x5728;strict&#x6A21;&#x5F0F;&#x4E0B;&#xFF0C;&#x4F60;&#x4F1A;&#x5F97;&#x5230;&#x4E00;&#x4E2A;&#x9519;&#x8BEF;:</p>
<pre><code class="lang-javascript"><span class="hljs-keyword">var</span> xiaoming = {
    name: <span class="hljs-string">&apos;&#x5C0F;&#x660E;&apos;</span>,
    birth: <span class="hljs-number">1990</span>,
    age: <span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params"></span>) </span>{
        <span class="hljs-keyword">var</span> y = <span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>().getFullYear();
        <span class="hljs-keyword">return</span> y - <span class="hljs-keyword">this</span>.birth;
    }
};

<span class="hljs-keyword">var</span> fn = xiaoming.age;
fn(); <span class="hljs-comment">// Uncaught TypeError: Cannot read property &apos;birth&apos; of undefined</span>
</code></pre>
<h3 id="apply">apply</h3>
<p>&#x867D;&#x7136;&#x5728;&#x4E00;&#x4E2A;&#x72EC;&#x7ACB;&#x7684;&#x51FD;&#x6570;&#x8C03;&#x7528;&#x4E2D;&#xFF0C;&#x6839;&#x636E;&#x662F;&#x5426;&#x662F;strict&#x6A21;&#x5F0F;&#xFF0C;<code>this</code>&#x6307;&#x5411;<code>undefined</code>&#x6216;<code>window</code>&#xFF0C;&#x4E0D;&#x8FC7;&#xFF0C;&#x6211;&#x4EEC;&#x8FD8;&#x662F;&#x53EF;&#x4EE5;&#x63A7;&#x5236;<code>this</code>&#x7684;&#x6307;&#x5411;&#x7684;&#xFF01;</p>
<p>&#x8981;&#x6307;&#x5B9A;&#x51FD;&#x6570;&#x7684;<code>this</code>&#x6307;&#x5411;&#x54EA;&#x4E2A;&#x5BF9;&#x8C61;&#xFF0C;&#x53EF;&#x4EE5;&#x7528;&#x51FD;&#x6570;&#x672C;&#x8EAB;&#x7684;<code>apply</code>&#x65B9;&#x6CD5;&#xFF0C;&#x5B83;&#x63A5;&#x6536;&#x4E24;&#x4E2A;&#x53C2;&#x6570;&#xFF0C;&#x7B2C;&#x4E00;&#x4E2A;&#x53C2;&#x6570;&#x5C31;&#x662F;&#x9700;&#x8981;&#x7ED1;&#x5B9A;&#x7684;<code>this</code>&#x53D8;&#x91CF;&#xFF0C;&#x7B2C;&#x4E8C;&#x4E2A;&#x53C2;&#x6570;&#x662F;<code>Array</code>&#xFF0C;&#x8868;&#x793A;&#x51FD;&#x6570;&#x672C;&#x8EAB;&#x7684;&#x53C2;&#x6570;&#x3002;</p>
<p>&#x7528;<code>apply</code>&#x4FEE;&#x590D;<code>getAge()</code>&#x8C03;&#x7528;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">getAge</span>(<span class="hljs-params"></span>) </span>{
    <span class="hljs-keyword">var</span> y = <span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>().getFullYear();
    <span class="hljs-keyword">return</span> y - <span class="hljs-keyword">this</span>.birth;
}

<span class="hljs-keyword">var</span> xiaoming = {
    name: <span class="hljs-string">&apos;&#x5C0F;&#x660E;&apos;</span>,
    birth: <span class="hljs-number">1990</span>,
    age: getAge
};

xiaoming.age(); <span class="hljs-comment">// 25</span>
getAge.apply(xiaoming, []); <span class="hljs-comment">// 25, this&#x6307;&#x5411;xiaoming, &#x53C2;&#x6570;&#x4E3A;&#x7A7A;</span>
</code></pre>
<p>&#x53E6;&#x4E00;&#x4E2A;&#x4E0E;<code>apply()</code>&#x7C7B;&#x4F3C;&#x7684;&#x65B9;&#x6CD5;&#x662F;<code>call()</code>&#xFF0C;&#x552F;&#x4E00;&#x533A;&#x522B;&#x662F;&#xFF1A;</p>
<ul>
<li><code>apply()</code>&#x628A;&#x53C2;&#x6570;&#x6253;&#x5305;&#x6210;<code>Array</code>&#x518D;&#x4F20;&#x5165;&#xFF1B;</li>
<li><code>call()</code>&#x628A;&#x53C2;&#x6570;&#x6309;&#x987A;&#x5E8F;&#x4F20;&#x5165;&#x3002;</li>
</ul>
<p>&#x6BD4;&#x5982;&#x8C03;&#x7528;<code>Math.max(3, 5, 4)</code>&#xFF0C;&#x5206;&#x522B;&#x7528;<code>apply()</code>&#x548C;<code>call()</code>&#x5B9E;&#x73B0;&#x5982;&#x4E0B;&#xFF1A;</p>
<pre><code class="lang-javascript"><span class="hljs-built_in">Math</span>.max.apply(<span class="hljs-literal">null</span>, [<span class="hljs-number">3</span>, <span class="hljs-number">5</span>, <span class="hljs-number">4</span>]); <span class="hljs-comment">// 5</span>
<span class="hljs-built_in">Math</span>.max.call(<span class="hljs-literal">null</span>, <span class="hljs-number">3</span>, <span class="hljs-number">5</span>, <span class="hljs-number">4</span>); <span class="hljs-comment">// 5</span>
</code></pre>
<p>&#x5BF9;&#x666E;&#x901A;&#x51FD;&#x6570;&#x8C03;&#x7528;&#xFF0C;&#x6211;&#x4EEC;&#x901A;&#x5E38;&#x628A;<code>this</code>&#x7ED1;&#x5B9A;&#x4E3A;<code>null</code>&#x3002;</p>

                                
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